If the lines represented by the equation 2 x 2 - p x y + 2 y 2 = 0 are real then the value of ' p ' lies in the interval

Step-by-step solution

As we know, a x 2 + 2 h x y + b y 2 = 0 , represents a pair of straight lines when h 2 - a b ≥ 0 So, 2 x 2 - p x y + 2 y 2 = 0 represent pair of straight lines iff p 2 4 - 4 ≥ 0 ⇒   p - 4 p + 4 ≥ 0 p ∈ - ∞ , - 4 ∪ 4 , ∞